1. Field of the Invention
The present invention relates to a motor structure having a connector or terminal block, to which a conductively caulked terminal is connected.
2. Description of the Related Art
In a motor structure wherein a wire is wound onto a stator core and an end of the wire is connected to a terminal block or a connector, many man-hours are necessary to remove a wire coating. As a technique for reducing the man-hours for removing the coating, conductive caulking may be used. Conductive caulking is a manufacturing technique, wherein a wire is covered by a terminal and large current is applied to the terminal so that a coating of the wire is evaporated by heat. For example, Japanese Unexamined Patent Publication (Kokai) No. 2004-343831 discloses an electric motor, and describes that “ends of lead wires 21U, 21V and 21W of each phase of a stator coil in electric motor 20 are connected to ends of conductive members 12U, 12V and 12W corresponding to each phase of relay member 10 by means of conductive caulking member 22.”
Japanese Unexamined Patent Publication (Kokai) No. 2009-303300 discloses a three-phase electric motor and describes that “as shown in FIG. 2(a), one coil lead wire B1 is inserted into butt terminal 31 from one end thereof. Then, by using conductive caulking machine 40, butt terminal 31 is caulked so that lead wire B1 is fixed to butt terminal 31 (see calked mark 31b). Next, corresponding connector lead wire A1 is inserted into butt terminal 31 from the other end thereof. Lead wire A1 is inserted until lead wire Al abuts lead wire B2 within butt terminal 31. By virtue of this, lead wire A1 is electrically communicated with lead wire B1.”
Japanese Unexamined Patent Publication (Kokai) No. 2010-110168 discloses a terminal connecting method and apparatus wherein the connection between a coil end and a terminal is automated, and describes that “conductive caulking device 138 is a robot having a multi-joint arm, and movable electrode 138a and fixed electrode 138b for conductive caulking are arranged on a front end of the arm. Conductive caulking device 138 carries out conductive caulking by clamping terminal 210 between movable electrode 138a and fixed electrode 138b and applying current to the electrodes.”
Japanese Unexamined Patent Publication (Kokai) No. 2000-69705 discloses a stator of a rotating electric machine and describes that “the other end of common-mode coil connecting wire 24 is inserted into annular portion 28a of one phase terminal 28, as shown in FIG. 2, and is connected and fixed by crimping, ultrasonic welding or conductive caulking. In the case of FIG. 1, two common-mode coils 18a and two common-mode coils 18b (i.e., four coils) are provided. Ring portion 28a of phase terminal 28 is fixed to a corresponding terminal of power cable terminal block 20 (for example, U-phase terminal 20a) by means of a fixing means such as a screw, after coil 18a (18b) is inserted into slot 16a of stator core 16.”
On the other hand, a technique for conserving space and the number of components has been disclosed. For example, Japanese Unexamined Patent Publication (Kokai) No. 11-150904 discloses a stator connecting terminal and describes that “in FIGS. 6 to 8, first connecting terminal 451 is formed by conductive metal, wherein outer wire connecting terminal potion 48 which is inserted into and fixed to first fitting hole 391 so that one end of the portion projects from first fitting hole 391, flat connecting plate portion 49 having one end which is vertically connected to the other end of terminal portion 48, and coil connecting terminal portion 50 connected to the other end of plate portion 49, are integrally constituted. Before first connecting terminal 451 is assembled to stator 21, coil connecting terminal portion 50 is vertically connected to connecting plate portion 49 and extends in the direction opposed to terminal portion 48 (i.e., the direction away from bobbin 34 when terminal portion 48 is inserted into first fitting hole 391). In this regard, coil connecting terminal portion 50 may be bent so as to overlap connecting plate portion 49.”
Further, Japanese Unexamined Patent Publication (Kokai) No. 2008-295213 discloses a structure and method for motor coil connection and describes that “FIG. 1 shows an example of a coil connecting structure which is one embodiment of the present invention. Conductors 11 are formed of a conductively caulkable material such as copper. One end of each conductor 11 is formed into the shape of a terminal as a terminal-shaped portion 10, and the other end is mounted on power input section (connector) 12. Conductors 11 are formed so as to conform to the shape of coil ends of a stator coil and maintain that shape, and therefore conductors 11 do not protrude outside the electric motor.”
In Japanese Unexamined Patent Publication (Kokai) No. 2004-343831, the lead wire of the stator coil and the conductive member are inserted into the sleeve-shaped conductive caulking member while being overlapped with each other, and the lead wire is connected to the connector by means of the relay member having the conductive member. In Japanese Unexamined Patent Publication (Kokai) No. 2009-303300, one end of the coil lead wire and one end of the connector lead wire are electrically connected by conductive caulking within the butt terminal, and the other end of the connector lead wire is connected to the connector. Further, in Japanese Unexamined Patent Publication (Kokai) No. 2010-110168, the robot having the multi-joint arm carries out conductive caulking so as to automate the connection between the coil end and the terminal.
However, none of Japanese Unexamined Patent Publication (Kokai) No. 2004-343831, Japanese Unexamined Patent Publication (Kokai) No. 2009-303300 and Japanese Unexamined Patent Publication (Kokai) No. 2010-110168 explains the connecting manner between the terminal conductively caulked at the coil side and the connector or the terminal block. Further, in Japanese Unexamined Patent Publication (Kokai) No. 2000-69705, the ends of the plurality of coils are conductively caulked to the round terminal, and the round terminal is connected to the terminal block. However, the round terminal is connected to the terminal block by means of a screw. As described above, in the conventional method, a large space may be necessary for the screw connection of the caulked terminal, layout of the coil and/or the lead wire, and the insulation between the components, etc. In addition, when the relay member is used, the number of the components may be increased.
On the other hand, it could be understood that the technique in Japanese Unexamined Patent Publication (Kokai) No. 11-150904 is intended to provide the special and bendable structure to the connecting terminal so that the space may be conserved by bending the connecting terminal after the lead wire is conductively caulked, on the ground that it is necessary to position the connecting terminal at a distance from the coil having the core in order to carry out the conductive caulking of the lead wire. Further, it could be understood that the technique in Japanese Unexamined Patent Publication (Kokai) No. 2008-295213 is intended to conserve the space by using the special integrated connector having the insulating member and the conductor. However, such a specially structured terminal or integrated connector may be expensive.